Lot's of leveraged houses vs. one or two paid off houses

[Jack B.]

 I know that they say leverage allows you to increase your returns, however; I've heard a popular investor say that he used to think that many leveraged properties were the way to go, but that now he realizes that one or two paid off properties that cash flow like crazy are the better way to go. But he doesn't say WHY.

The one thing that comes to mind is if you have 50 leveraged houses, you have 50 roofs to deal with, 50 kitchens, etc. That's a lot of money spent on upkeep, but if it is factored into the rents and budgeted for, then I don't see why this still isn't a better way to go. Perhaps it's the way to go when building wealth, but paid off properties are good for when you want to "retire".

Thoughts?